The third generation partnership project (3GPP) is a joint venture of international standards bodies for the promotion of high-speed cellular services that are commonly referred to as 3G. 3GPP provides specifications for global system for mobile communications (GSM) carriers, and 3GPP2 relates to code division multiple access (CDMA) carriers. 3GPP maintains general packet radio service (GPRS), which is a packet oriented mobile data service that allows second generation (2G), 3G, and wireless CDMA (WCDMA) networks to transmit Internet protocol (IP) packets to external networks. 3GPP defines two network sharing architectures, namely multiple operator core network (MOCN) and gateway core network (GWCN) architectures. MOCN allows sharing of only the radio access network (RAN), whereas GWCN allows RAN sharing as well as sharing of gateway nodes, such as the mobile switching center (MSC) and serving GPRS support node (SGSN).
Currently, 3GPP compliant devices can select any public land mobile network (PLMN) that is broadcasted over the air, even if that PLMN is not explicitly configured by a home operator on the universal integrated circuit card (UICC) preferred PLMN lists. Typically, roaming agreements are configured on the network in terms of allowed PLMNs associated with authorized roaming partners. A mobility management entity (MME) typically performs a gatekeeping function via a roaming database that helps the MME cross check which roaming subscribing devices to let through using the service provider PLMN that is broadcast over the air interface.